A vehicle is provided with a muffler for reducing or deadening exhaust noise of exhaust gas from an internal combustion engine (e.g., Patent Documents 1 to 3, and see FIGS. 6A, 6B in this application).
A muffler of this type includes: a cylindrical outer shell of flat cross-section; end plates closing openings at both ends of the outer shell; an inlet pipe for introducing exhaust gas into the outer shell; separating plates for sectioning the inside of the outer shell, thereby defining a plurality of muffling chambers; and an outlet pipe for expelling exhaust gas out of the outer shell from inside it.
A muffler described in Patent Document 1 is a so-called longitudinally-mounted type muffler, in which the direction of the long axis of the outer shell extends along the forward and backward directions of the vehicle. A straight inlet pipe is disposed along the direction of the long axis of the outer shell and through an end plate and separating plates (see FIG. 1 in Patent Document 1).
Meanwhile, laterally-mounted type mufflers as disclosed in Patent Documents 2, 3 have been developed due to the limits of muffler installation space. A muffler of this type is disposed such that the direction of the long axis of the outer shell extends along the direction of the vehicle width (i.e., such that the direction of the short axis of the outer shell extends along the forward and backward directions of the vehicle). Because of this, the inlet pipe is generally inserted into the outer shell from the direction of the short axis of the outer shell (see FIGS. 1, 2 in Patent Document 2, and FIG. 1 in Patent Document 3).
FIG. 6A is an overall view showing an installation example of a muffler (e.g., a laterally-mounted type muffler), and FIG. 6B is an enlarged view of the installed portion of the muffler. The vehicle shown in FIGS. 6A, 6B is of sedan type. In a vehicle of this type, a muffler is generally disposed below luggage space in the rear of the vehicle. Generally, since an internal combustion engine is disposed in the front area of the vehicle, the inlet pipe projects in the frontward direction of the vehicle along the direction of the short axis of the muffler.